Vaisala HMM105 Digital Open Frame Humidity Module


  • Digital I2C communication interface available
  • Full temperature compensation over the operating temperature range of -40 °C … +180 °C
  • High-temperature tolerance, suitable for heat sterilization up to +200 °C
  • Vaisala HUMICAPâ 180R sensor
  • Detachable probe assembly
  • Probe head with M10x1 threads
  • Applications: test chambers, incubators

Dpstar is a leader in environmental and industrial measurements. Curiosity and innovation are core values in our company. Our extensive knowledge and expertise are materialized in our selection of innovative products. Accurate measurements are essential for healthy indoor air and improving the energy efficiency of buildings. The unique, cutting-edge Dpstar sensor technologies are manifested throughout our versatile range of products. The transmitters have an exceptionally long lifetime and excellent measurement stability, thus being practically maintenance-free. These are among the many reasons why Dpstar’s products are a sustainable choice.

Vaisala HMM105 Digital Open Frame Humidity Module an open frame module for integration into environmental chambers. The modules provide an I2C output for relative humidity (RH) or dew point (Td). The module consists of a detachable probe assembly – a probe head with M10x1 threads and a flex cable – and the module circuit board. The probe assembly is 30 cm in length. The module incorporates the HUMICAP 180R sensor which ensures excellent measurement accuracy.



  • Easy installation
  • Excellent measurement accuracy
  • Maintenance-free

Reliable for OEM’s

Vaisala HMM105 probe head works in freezing conditions (-40 °C) and also in temperatures up to +180 °C in continuous use. In short-term use, the probe head can be exposed to temperatures up to +200 °C. HMM105 is intended for OEM chamber manufacturers for integration into test chambers and incubators.

I2C interface for better usability

Vaisala HMM105 has an I2C interface for communicating with the incubator’s controller. HMM105 implements I2C slave functionality, with the incubator’s controller acting as the master. The interface can be used to read measurement values and status information, set operation parameters, and make adjustments.

Maintenance free

Compared to psychrometers, Vaisala HMM105 is practically maintenance-free. There is no wick that needs changing and there is no need for a water tank or water pump. Thus, environmental stress screening can be done reliably.


It’s an open frame module designed to fit into environmental chambers and incubators. Inside, it has the Vaisala HUMICAP 180R sensor, guaranteeing precise measurements. It’s a dependable option for OEM applications.


Relative Humidity
Measurement range 0 … 100 %RH
Factory calibration uncertainty (+20 °C) ±1.5 %RH
Humidity sensor HUMICAP 180R
Accuracy (incl. Non-Linearity, Hysteresis and Repeatability)
Temperature -20 … +40 °C
0 … 90 %RH ±2 %RH
90 … 100 %RH ±3 %RH
Temperature 40 … -20 °C, +40 … +180 °C
0 … 90 %RH ±2.5 %RH
90 … 100 %RH ±3.5 %RH
Dew Point Temperature
Measurement range -20 … +100 °C (-4 … +212 °F)Td
Accuracy (incl. non-linearity, hysteresis and repeatability) when dew point depression < 20 °C (Ambient temperature – dew point) ±2 °C Td
Operating Environment
EMC compliance Applicable parts of EN61326-1, Industrial Environment
Storage temperature -40 … +75 °C (-40 … +167 °F)
Operating Temperature
Component board -5 … +55 °C (+23 … +131 °F)
Probe (continuous use) -40 … +180 °C (-40 … +356 °F)
Probe (short term peak) +200 °C (+392 °F)
Plastic grid, membrane filter -20 … +80 °C (-4 … +176 °F)
PTFE sintered filters, stainless steel sintered filter -40 … +200 °C (-40 … +392 °F)
Inputs and Outputs
Supply voltage 10 … 35 VDC, 24 VAC (±20 %)
Output voltage I2C 5 V
Power consumption (DC/AC) < 15/25 mA
Connector for supply voltage and I2C bus Molex 87832-1007, 10-pin header
Probe diameter 12 mm
Probe flex cable length 0.3 m
Probe lead-through material PPS plastic
Spare Parts and Accessories
Humidity sensor HUMICAP 180R
Short PTFE sintered filter DRW239993SP
Plastic grid filter 6221
Plastic grid and membrane filter 10159HM
PTFE sintered filter 219452SP
Stainless steel sintered filter HM47280SP
0.6 m cable with Molex milli-grid connectors ASM210962SP


Vaisala HMM105 Digital Open Frame Humidity Module_DpstarGroup